METHOD FOR PRODUCING POLY(VINYL ALCOHOL) POLARIZING FILM IODINATED AT SOLUTION STATE BEFORE CASTING

摘要

PURPOSE: A method for producing a polarizing film is provided to prepare a polarizing film with excellent polarity and durability by adding iodine and boric acid to a polyvinyl alcohol aqueous solution, and to increase productivity of a polarizing film. CONSTITUTION: A method for producing a polarizing film using a poly(vinyl alcohol) resin iodinated in a solution state comprises the steps of: (100) diluting polyvinyl alcohol in water to obtain a polyvinyl alcohol aqueous solution; (200) adding iodine and potassium iodide and boric acid while keeping the polyvinyl alcohol aqueous solution at a constant temperature and then dissolving the materials in the aqueous solution; (300) molding the polyvinyl alcohol aqueous solution in which additive is dissolved in a film form; (400) drawing the molded polyvinyl alcohol film using a solvent; and (500) drying the drawn film.